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Process for production of an effervescent alcoholic beverage

Process for production of an effervescent alcoholic beverage description/claims

1. Field of the Invention

The present invention relates to a process for production of an effervescent alcoholic beverage.

2. Related Background Art

Flavor is an important factor that determines the quality of effervescent alcoholic beverages brewed using yeast. Much research has been conducted with the main goal of developing, for example, beer, low-malt beer (happoshu), wine, sake and other brewages with flavors suited to consumer tastes.

Among factors that influence the flavor of effervescent alcoholic beverages, sulfur-containing compounds are well-known as a factor that negatively affect the flavor of effervescent alcoholic beverages brewed using yeast, and reduction of sulfur-containing compounds produced by yeast is considered to help improve the flavor and quality of effervescent alcoholic beverages.

Particularly in the case of low-malt beer brewed by fermenting low-nitrogen wort and effervescent alcoholic beverages brewed using pea, soybean or the like as a raw material instead of malt or barley, hydrogen sulfide, which causes sulfur odor, may remain in the final product, and its adverse effect on flavor and quality of the alcoholic beverage poses a major problem for product development.

Several measures for inhibiting production of sulfur-containing compounds by yeast have therefore been proposed. Examples of measures that have been proposed include: a method wherein an excess of hydrogen sulfide metabolites are added to the raw material solution during the main fermentation step, in which the yeast actively carries out alcohol fermentation, to cause feedback inhibition of hydrogen sulfide production; and a method wherein a brewer's yeast strain with low hydrogen sulfide production is selected for brewing.

In this regard, it has been reported that in the case of bottom-fermenting yeast used for beer brewing, increase of the methionine concentration or ammonium ion concentration in the wort during the main fermentation step causes feedback inhibition of hydrogen sulfide production (J. ASBC, 2004, Vol. 62, No. 1, p. 35-41).

Also, wine yeast strains for use in wine brewing which are resistant to sulfur-containing amino acid analogs (for example, ethionine, selenomethionine and S-ethylcysteine) have been reported as yeast strains with low hydrogen sulfide production (Japanese Patent Application Laid-Open No. 08-214869).

Gene recombination has also been used to create numerous yeast strains with low hydrogen sulfide production (Japanese Patent Application Laid-Open No. 05-192155; Japanese Patent Application Laid-Open No. 05-244955; Japanese Patent Application Laid-Open No. 2005-065572; Japanese Patent Application Laid-Open No. 07-303475).

However, if sulfur-containing amino acid analogs are added to the raw material solution or the methionine concentration or ammonium ion concentration of the raw material solution is increased during the main fermentation step, in which the yeast actively carries out alcohol fermentation, this also poses problems, such as lowering of the fermentation rate and reduction of the amount of main flavor components.

Also, yeast strains created by gene recombination contain a promoter gene or drug resistance gene of different species that is not found in natural yeast. Therefore, from the viewpoint of safety, it has been difficult to use them in the brewing of effervescent alcoholic beverages and the like for human consumption.

It is an object of the present invention to provide: a process for producing an effervescent alcoholic beverage which has a low hydrogen sulfide concentration and an excellent flavor without using gene recombination, while avoiding adverse effects on the main fermentation step.

The present inventors found that the amount of hydrogen sulfide in an effervescent alcoholic beverage is negatively correlated with the pH of the fermentate in the storage step during which the fermentate is aged, and that by keeping the pH of the fermentate within a fixed range during the storage step, it is possible to obtain an effervescent alcoholic beverage having a low hydrogen sulfide concentration and an excellent flavor. The present invention was completed on the basis of this finding.

The present invention provides a process for production of an effervescent alcoholic beverage, the process comprising: a pH adjusting step in which the pH of a yeast-containing fermentate obtained by fermenting the raw material of an effervescent alcoholic beverage with the yeast is adjusted, and a storage step in which the fermentate is aged to yield an aged liquor.

Production steps for effervescent alcoholic beverages using yeast are generally divided into the following three steps: a mashing step in which a raw material mixture comprising the principal raw material (malt, barley, rice, pea, soybean, corn or the like) and water is warmed; a main fermentation step in which sugar (extract) in the raw material mixture (raw material solution) is decomposed into alcohol and carbon dioxide gas with yeast to accomplish alcohol fermentation; and a storage step in which the sugar (extract) remaining in the fermentate obtained from the main fermentation step is re-fermented at low temperature and the fermentate is aged. The main fermentation step and storage step have been carried out in series, and adjustment of the pH between these steps has not been performed.

However, if a pH adjusting step is carried out between the main fermentation step and storage step for adjustment of the pH of the yeast-containing fermentate after the main fermentation step as in the process of the invention, it is possible to reduce the hydrogen sulfide concentration of the final product (effervescent alcoholic beverage), and to improve the flavor of the effervescent alcoholic beverage.

Also, the process of the invention makes it possible to produce an effervescent alcoholic beverage while avoiding lowering of the fermentation rate and reduction of the amount of main flavor components. Also, the process of the invention, in which gene recombination does not need to be used, makes it possible to produce an effervescent alcoholic beverage that is safe for the human body. Also, the process of the invention, in which it is not necessary to breed a yeast using a yeast strain resistant to sulfur-containing amino acid analogs, makes it possible to control costs for development of effervescent alcoholic beverages.

As described above, the process of the invention makes it possible to produce an effervescent alcoholic beverage which has a reduced concentration of hydrogen sulfide and an improved flavor, compared to an effervescent alcoholic beverage produced without performing the pH adjusting step. Therefore, the process of the invention is also a process for production of an effervescent alcoholic beverage having an improved flavor, and a process for production of an effervescent alcoholic beverage having a reduced concentration of hydrogen sulfide.

The pH adjusting step is preferably a step in which the pH of the fermentate is adjusted so that the pH of the effervescent alcoholic beverage to be produced is 4.0 to 5.0, and more preferably so that the pH of the effervescent alcoholic beverage is 4.09 to 4.65.

If the pH of the effervescent alcoholic beverage is 4.0 to 5.0, the hydrogen sulfide concentration and sulfur odor of the beverage can be significantly reduced, and consumers will be able to drink the beverage almost without noticing any sulfur odor. Moreover, if the pH of the effervescent alcoholic beverage is 4.09 to 4.65, generation of stuffy smell or the like can be sufficiently prevented, and the flavor and quality of the beverage can be further improved.

• Provisional Patent
• Utility Patent

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